Boiler tube and end-plate connection



C. S. COLEMAN.

BOILER TUBE AND END PLATE CONNECTION.

APPLICATION F ILED FEB. 12, 19w.

1,340,118. Patented May11,1920. I

INVENTOR.

[hr/e5 5. 6' 0/6014)? A TTORNEY UNITED STATES PATENT OFFICE.

CHARLES S. COLEMAN, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO COLEMAN BOILER APPLIANCE COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF DELAWARE.

BOILER TUBE AND END-PLATE CONNECTION.

Specification of Letters Patent.

Patented May 11, 1920.

Application filed February 12, 1917. Serial No. 148,106.

To all whom it may concern:

Be it known that 1, CHARLES S. COLEMAN, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful'Boiler Tube and End-Plate Connection, of which the following is a specification.

My invention relates to boiler tube and end plate connections and articularly pertains to improvements in t e form of such connections shown in United States Patent No. 949,621, issued to me February 15, 1910.

It is the purpose of my present invention to provide a construction whereby the joint between the tube and end plate will be rendered substantially leak proof .and in which expansion and contraction of the tube and the consequent pull and pressure exerted on the joint will not tend to weaken same. A

A prime object of my invention is to provide a construction by which the copper gasket commonly employed in such oints will be concealed both interiorly and exteriorly of the end plate so that it will not be subject to the corrosive action of water in the boiler or to the action of flames and gases in the combustion chamber.

A further object is to provide a double wedge connection between the tube and end plate by which the tube and plate are securely keyed together and eflectlvely held against separation. Y

Other objects will appear hereinafter.

The invention is illustrated in the accompanying drawings, in which:

Figure 1 .is a view in vertical sectlon showing the manner of forming the connection between the tube and the plate.

Fig. 2 is a detail in perspective of the tube point. I j

Fig. 3 is a detail in perspective showlng the formation of the. opening in the tube plate for the reception of the tube end.

F i 4 is a detail section showing a modified form of the connection.

In carrying out this invention the tube plate 5 is formed with a tube receiving opening having diflerential diameters to form an annular shoulder 6 a short distance from the marginal edge of the opening on the inner face of the plate. The wall 7 of the opening, extending from the shoulder 6 to the outer or fire box face of the plate is verge oppositely to each other and thereby present opposite inclined faces through any section of the edge of the opening.

The tube end 9 is formed with a reduced portion 10 terminating at its inner end in a shoulder 11 and the outer surface of the tube is slightly beveled at its juncture with the shoulder 11 to conform with the bevel of the wall 8. However, the bevel of the wall 8 andthe tube may be dispensed with and this wall of the inner portions of the opening formed of equal diameter throughout so as to conform to the tube with a driving fit, as shown in Fig. 1.

In making the joint, a copper gasket 12 having an outwardly extending annular flange 13 on one end thereof is inserted in the large end of the opening to seat the flange 13 on the shoulder 6. The outer portion of the gasket is then rolled to conform to the wall 7 and theouter edge of the gasket is beaded over the outermarginal edge of the opening. I

The reduced end of the tube is then inserted through the opening from the inside -of the plate with the shoulder 11 abutting the gasket thereon, thus flaring the end of the tube as shown in Fig. 1. This flare of the-tube forms a wedge which opposes withdrawal of thetube and serves in cooperation with the shoulders to bind the tube in close engagement with the plate.

The outer end of the tube is then beaded I over, as indicated at 14, as is common in boiler construction, and this bead is extended to cover the outer end of the asket and protect it against direct action of heat and gases in the combustion chamber.

The action of the joint is as follows Longitudinal expansion of the tube causes the shoulder 11 thereof to bear upon the shoulder 6 of the plate through the flange of the gasket, thus not tending to shift the tube in its joint nor to force the beaded end thereof away from the outer face of the plate. Inward pull of the tube caused by V longitudinal contraction thereof is delivered to the plate through the bead and throughout the beveled wall 7. This prevents any tendency of the shoulder 11 of the tube to pull away from its seat.

The diametrical expansion and contraction of the tube in relation to the plate will be very slight if any; but such as might occur will not tend to separate or open the joint by reason of the contacting shoulders of the tube and plate being held in close engagement by the action of the flared and beaded connection between the outer portion of the tube and plate.

From the foregoing it will be seen that I have'provided a tube and sheet connection for boilers which is durable and practically non-leakable.

I claim:

1. The combination with a tube sheet having an opening of differential diameters to form an annular shoulder between the ends of the opening, the side walls of the opening on opposite sides of the shoulder being beveled outwardly forming oppositely inclined walls, of a soft metal gasket comprising a cylinder having a flange on one end adapted to seat on the shoulder, said gasket formed to conform to the outer inclined wall of the opening and beaded over the margin of the latter, and a tube point having a reduced portion at its outer end, the same terminating in a shoulder adapted to seat on the flange of the gasket, and having a beveled wall conforming to the inner beveled wall of the opening, the outer end of said tube being turned outward against the gasket and beaded over the outer end of the latter.

2. The combination of a tube sheet having a flue end receiving opening the walls of which taper and converge from the outside of the tube sheet inward, a counterbore around the margin of the opening on the inner face of the tube sheet the walls of which taper and converge from the inner face of the tube sheet, a shoulder at the convergent ends of the opening and counterbore facing the inside of the sheet, a soft metal gasket having a cylindrical wall terminating at one end in an outward flange, said gasket arranged with the flange seating on the countersunk shoulder and with the wall of the gasket expanded over the tapered wall of the opening and with its outer end beaded over the outer face of the tube sheet, and a flue point of an outside diameter to flt the counterbore and having a reduced end portion with a shoulder at the base of the the outer face of the tube sheet to conceal the gasket bead.

3. The combination of a tube sheet having a flue end receiving opening the walls of which taper and converge from the outside of the tube sheet inward, a counterbore around the margin of the opening on the inner face of the tube sheet, a shoulder at the convergent end of the opening at the base of said counterbore facing the inside of the sheet, a soft metal gasket having a cylindrical wall terminating at one end in an outward flange, said gasket arranged with the flange seating on theshoulder and with the wall of the gasket expanded over the tapered wall of the opening and with its outer end headed over the outer face of the tube sheet, and a flue point of an outside diameter to fit the counterbore and having a reduced end portion with a shoulder at the base of the reduced portion, said shoulder abutting on the flange of said gasket and the reduced portion expanded to flare outwardly against the gasket throughout the width of the opening wall, the outer end of the flue point beaded over the bead on the gasket and onto the outer face of the tube sheet to conceal the gasket head.

4. The combination of a tube sheet having a flue end receiving opening the walls of which taper and converge from the outside of the tube sheet inward, a counter-bore around the margin of the opening on the inner face of the tube sheet, a shoulder at the convergent end of the opening at the base of said counterbore facing the inside of the sheet, a soft metal gasket having a cylindrical wall terminating at one end in an outward flange, said gasket arranged with the flange seating on the shoulder and with the wall of the gasket expanded over the tapered wall of the opening and with its outer end beaded over the outer face of the tube sheet, the flange on said gasket having a thickness less than the depth of the counterbore so that its outer face will be counter-sunk within the counter-bore, and a flue point of an outside diameter to fit the counter-bore and having a reduced end portion with a shoulder at the base of the reduced portion, said shoulder abuttingv on the flange of said gasket concealing the flange within the counterbore, the reduced portion of said flue point expanded to flare outwardly against the gasket throughout the width of the opening wall, the outer end of the flue point being beaded over the bead on the gasket and onto the outer face of the tube sheet to conceal the gasket bead.

5. The combination of a tube sheet having a flue end receiving opening, a counterbore around the margin of the opening on the inner face of the tube sheet, a shoulder at the base of said counterbore, a soft'metal gasket having a cylindrical wall terminating at one end in an outwardly projecting flange adapted to seat onsaid shoulder with the wall of the gasket extending over the 10 outer portion of the wall of the opening,

said flange having a thickness less than the depth of the counterbore so that its outer face will be countersunk within the counterbore, and a flue point of an outside diameter to fit the counterbore and having a reduced portion with a shoulder at the base of the reduced portion, said shoulder abutting on the flange of said gasket and concealing the flange within the counterbore.

' CHARLES S. COLEMAN. 

